Hin Sotheany, a former analyst for the Office of the Co-Investigating Judges (OCIJ) who helped compile the Khmer Rouge tribunal’s list of S-21 detainees, testified there yesterday on the nature and findings of her research.

Sotheany, who also once worked for the Documentation Centre of Cambodia (DC-Cam), told the court that she recorded 15,101 prisoners entering the S-21 prison centre during the Khmer Rouge regime.

However, Victor Koppe, defence lawyer for former Khmer Rouge second-in-command Nuon Chea, asked Sotheany how she knew documents used in her project were authentic.

Sotheany responded that she had authenticated documents based on format, logos and signatures, but admitted that forensic analysis was not used.

Koppe also pointed out that some prisoners were labelled as executed, while other documents claim the same prisoner died of disease.

“In my list, I focused and relied on the incoming prisoners list. If there was a note at the end that this person died of disease, then I would make a reference to that note,” the witness answered, clarifying that her primary role was compiling data on incoming detainees, not executions.

Sotheany also told the court that she took particular care to avoid duplicate entries of prisoner names on the OCIJ list.

“If there are other documents that refer to a particular prisoner’s name or a similar name then I would refer to the date of birth or place of arrest,” she said.

Prosecutor Dale Lysak, meanwhile, suggested that the actual number of executions was in fact much higher than what is currently reported by OCIJ documents.

“There are an additional 1,650 executions that would be added to the 5,500 that already appear - this is just the start,” Lysak said, predicting that even more executions would be added to that number eventually.

Sotheany admitted she hadn’t had time to record every execution and repeated that it wasn’t her main focus.

“It will be much, much higher than 6,600. But this witness should not be encouraged to speculate,” Lysak said.

Sotheany declined to provide an estimate.

After the trial, DC-Cam director Youk Chhang said that even if not all the deaths at S-21 were executions, the leaders of the Khmer Rouge are still responsible for the deaths that occurred from disease and starvation.

“Some died of disease, some died of exhaustion after being severely tortured. There was no proper food, no hygiene no medicine,” he said.